The field of the invention is centrifugal air filters, and more particularly, centrifugal grease extractors for commercial kitchens.
Centrifugal air filters are used to extract impurities suspended in air by causing the air to enter a helical path in a vortex chamber and subjecting the impurities to a centrifugal force. The impurities are propelled away from the vortex center and impinge upon chamber walls. The air exits the vortex chamber leaving the impurities behind in the chamber.
One particular use for centrifugal air filters is to extract impurities, such as grease, from grease-laden air formed in commercial kitchens during cooking. These grease extractors are typically a cleanable or replaceable component of kitchen ventilation systems disposed above a cooking area, such as a stove or the like. A fan in the ventilation system draws grease-laden air through the filter which extracts the grease from the air prior to exhausting the air into the atmosphere. The extracted grease runs down the filter walls and is collected for proper disposal.
One prior art centrifugal air purifier disclosed in U.S. Pat. No. 4,872,892, has parallel vortex chambers. Each chamber has a pair of inlets formed in the filter front. The grease-laden air enters one of the chambers through the chamber inlets and exits substantially perpendicular to the direction of entering air through outlets in the chamber ends. This particular configuration allows at least a portion of the grease-laden air to pass directly from the inlet to the outlet without being subject to the vortex action necessary to release the grease suspended in the air. Furthermore, this particular application cannot be mounted in a standard baffle filter hood. Because the ends of the filter must remain open, a special mounting bracket is required.